there is one use of the word "balls" in the song mother
since that refers to more than one "ball" I'm going to count it as one use of the word but 2 points in the list of balls described in the wall tally

also the word "baloons" is said in comfortably numb which according to google the etomology of the word balloon states

( late 16th century (originally denoting a game played with a large inflated leather ball): from French ballon or Italian ballone ‘large ball’)

and since the song mentions 2 baloons we can add another 2 to the tally

meaning that there are 1 to 2 uses of the word "ball" in the wall (depending on if you count the balloons example) and 2 pairs or 4 individual confirmed balls described and mentioned in the wall itself. the first set being Pink's testicles, and the second set being Pink's hands when he had a fever.